hydrocephalus (non-communicating)

Last reviewed 01/2018

Non-communicating hydrocephalus results from obstruction to CSF flow within the ventricular system. Fluid accumulates proximal to the site of the blockage causing dilation.

Complete blockage is untenable.

The aqueduct is the most narrow part of the normal CSF pathway and that most likely to become obstructed - the third and lateral ventricles will be dilated, the fourth will remain small.

All four ventricles are dilated when obstruction occurs at the level of the foramina of Luschka and Magendie, or the basal cisterns; causes of this include:

  • congenital: Dandy Walker and Arnold Chiari malformations
  • acquired - meningeal scarring due to meningitis, subarachnoid haemorrhage and cranial trauma