Fourth ventricular outlet obstruction

Case contributed by Dr Mostafa El-Feky


Headache. Known obstructive hydrocephalus on treatment for one year.

Patient Data

Age: 5 years
Gender: Female


Moderate to marked dilatation of the supratentorial ventricular system, with  morbidly dilated fourth ventricle. No periventricular CSF permeation. The mamillopontine distance = 1.2 mm "reduced".  Multiple thin septations seen at the subarachnoid spaces notably at the prepontine region and at forth ventricle outlets. Prominent foramen Luschka bilaterally.


CSF flow study

CSF flow dynamic study with Ultra-thin 3D sagittal T2 weighted images & Phase contrast sequence revealed:

  • ultra-thin 3D sagittal T2W shows dilated patent aqueduct with unidirectional flow.  
  • increased estimated flow volume of around 736 microliters
  • peak velocity averages 7.46 cm/sec
  • suspected tiny spontaneous third ventriculostomy at the floor of the third ventricle

Case Discussion

Marked obstructive hydrocephalus due to fourth ventricular outlet obstruction by fine septations , partially compensated by small spontaneous third ventriculostomy. The condition is stationary for one year.           

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Case information

rID: 81615
Published: 16th Sep 2020
Last edited: 16th Sep 2020
Inclusion in quiz mode: Included

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