Hydrocephalus occurs when excessive cerebrospinal fluid accumulates in the brain. The name originated from the Greek words ‘hydro’ for water and ‘cephalus’ for head.
This is a relatively more common problem in the paediatric age group but adults acquire hydrocephalus because of accidents, tumours, bleeding or infection.
Left untreated, hydrocephalus can cause severe disability, even death.
Cerebrospinal fluid (CSF) is made up of water, minerals, nutrients and sugar. It is continually produced within the brain at the rate of 500 mL per day. The fluid flows through the four cavities (ventricles) in the brain, through the small openings (cisterns) at the base of the brain. Once it gets out from within the ventricles of the brain it bathes the surface of the brain and spinal cord and is then absorbed into the bloodstream. CSF aids in delivering nutrients to the brain and removing waste, keeping brain tissue buoyant and compensating for changes in blood volume in the brain and spinal cord.
When hydrocephalus occurs, it is a result of either a blockage to the flow of the CSF, or the body’s inability to absorb it. When this happens, the CSF builds up within the ventricles and in CSF compartments over the surface of the brain (subarachnoid space). The CSF build-up causes the ventricles and CSF compartments to swell or enlarge, which results in pressure on the brain or stretching of the nerve fibres connecting different parts of the brain. Without treatment, hydrocephalus results in compromised mental functioning, visual disturbances, walking difficulty, incontinence, and reduced conscious state.
Hydrocephalus may be caused three ways:
- 1.An increase in the production of cerebrospinal fluid
- 2.An obstruction to circulation within either the ventricles or subarachnoid space.
- 3.A failure of absorption.
Symptoms of hydrocephalus vary with age. The main symptoms in adults are headache, nausea and vomiting. Additional symptoms for adults may include: blurred or double vision, poor concentration, loss of muscle coordination, confusion, incontinence, and more rarely seizures or fits.
- A CT or MRI of the brain will show the widened ventricles and may also identify the cause of an obstruction (tumour)
- Lumbar puncture – can be done to establish if the pressure is elevated or not.
This usually requires surgery to insert a Shunt system which eases the build of CSF. There are two types of shunts that can be implemented
- Endoscopic third ventriculostomy – Involves making a hole in the third ventricle bypassing a blockage within the ventricular system.
- A ventriculo- peritoneal/Pleural shuntdiverts CSF out of the cranial cavity into the peritoneal cavity/pleural cavity. This shunt system usually consists of a ventricular catheter (a fine tube which is inserted into the brain - ventricle), a valve to release the fluid and, a distal catheter (a fine tube which is tunnelled under the skin to the abdominal/pleural cavity).