Hydrocephalus

Hydrocephalus is an abnormal build up of cerebrospinal fluid (CSF) within the ventricles of the brain. CSF is produced in a continuous fashion, flows through the ventricles and surrounds the brain and spinal cord. When there is a build-up of CSF, the pressure inside the head increases and this leads to symptoms.

In this article, we will discuss about:

The signs and symptoms by age
Causes of hydrocephalus
Diagnosis of hydrocephalus
Treatment
Summary

The signs and symptoms of hydrocephalus

Infants

  • Vomiting, sleepiness, irritability, poor feeding
  • Unusually large head, increase in head size
  • Poor growth

Adults

  • Headache
  • Lethargy
  • Impaired vision
  • Decline in memory and concentration
Older Adults
  • Loss of bladder control
  • Memory loss
  • Abnormal gait (shuffling or feeling of feet being stuck)
  • Poor balance

Causes of hydrocephalus

The build-up of CSF most commonly occurs due to obstruction of the flow of the CSF. Other causes are due to poor absorption or over-production of CSF.

An important cause of hydrocephalus in the elderly (in their 60-70’s) is Normal Pressure Hydrocephalus.

Normal Pressure Hydrocephalus (NPH)

NPH is a cause of hydrocephalus in the elderly. NPH is often misdiagnosed as Alzheimer or Parkinson disease because NPH patients also exhibit symptoms of dementia. Some statistics show that fewer than 20% of people with NPH are accurately diagnosed.

The three hallmark symptoms of NPH include walking problems, difficulty with memory (dementia), and loss of bladder control. NPH is one of the few causes of dementia that can be controlled or reversed with appropriate treatment.

Diagnosis of Hydrocephalus

Neurological history and examination

Brain imaging

CT Scan and MRI Scan

Cerebrospinal fluid tests

CSF tests are required sometimes and they include lumbar puncture, external lumbar drainage, CSF outflow resistance, intracranial pressure monitoring.

Treatment of Hydrocephalus

There are two main treatment methods both of which relies on redirecting the flow of cerebrospinal fluid.

1. Shunt

A device called a shunt is inserted. It consists of a long, flexible tube with a valve that keeps fluid from the brain flowing in the right direction. The shunt is placed such that the fluid is directed from the brain into another part of the body where it can be absorbed (e.g. in the abdomen). There are difference types of valves and different places where the shunt can be placed:
Types of valves
  • Programmable Valves
    ‍    In these, the valve pressure settings can be adjusted
  • Non programmable valves
    Fixed pressure
Placement of shunt
  • Ventriculoperitoneal shunt
    Brain ventricle to abdomen (most common in Singapore)
  • Ventriculoatrial
    Brain ventricle to heart chamber
  • Ventriculopleural
    ‍    Brain ventricle to chest
  • Lumboperitoneal
    Lumbar spinal canal to abdomen

2. Endoscopic third ventriculostomy

Endoscopic third ventriculostomy is an alternative to shunt implantation. This can be an option for some patients where the cause of the hydrocephalus is due to obstruction. A small hole is placed using an endoscope at the bottom of the third ventricle to bypass the usual flow of CSF. The main difference is that there is no requirement for a permanent implant and the operation can be performed through one incision.

Summary

Hydrocephalus can present with both acute and delayed symptoms.
The causes vary according to the age of the person.
Prompt medical attention is often required.