Post Haemorrhagic Ventricular Dilatation (PHVD)

Definitions:

  • Post haemorrhagic ventricular dilatation: Progressive accumulation of cerebrospinal fluid under pressure with enlargement of the ventricles.
  • Post haemorrhagic hydrocephalus: Progressive enlargement of the lateral ventricles until the ventricular width >4mm over the 97th centile for gestational age.

Measurements: The following measurements should be taken in PHVD to assess the overall distension of the ventricular system:

PHVD2PHVD3

The “ventricular index”, or more accurately, ventricular width is the distance between the midline and the mostlateral point of the lateral ventricle in millimetres measured in the coronal plane at the level of the foramen of Munro (Levene, Arch Dis Child 1981).

It is important to get a good symmetrical midline view. If the baby has a parenchymal haemorrhagic infarct or an evolving porencephalic cyst, the measurement should be taken from the opposite ventricle as shown below.

PHVD4

The rate of increase in ventricular size is more important than the absolute measurement. Measurements can be plotted on the Ventricular index chart: Levene VI chart

All infants with a large intraventricular haemorrhage (grade III), haemorrhagic parenchymal infarct or post haemorrhagic ventricular dilatation should be referred to the neonatal neurocritical care team.

The head circumference must be measured in any baby having a ventricular width measured.