Cerebral arterial and venous flow-velocity measurements in post-haemorrhagic ventricular dilatation and hydrocephalus.

Simultaneous anterior cerebral artery (ACA) and internal cerebral vein (ICV) flow-velocities were measured in 18 babies with post-haemorrhagic ventricular dilatation (PHVD) and hydrocephalus (PHH). Compared with a control group matched for post-conceptional age, the resistance index of the ACA was increased. This was shown to occur at an early stage of PHVD in a longitudinal study of seven of the babies. There were no significant changes in ACA or ICV time-averaged velocities. Eight babies with PHH had ventricular taps on 18 occasions to relieve raised intracranial pressure. There was a significant decrease in the resistance index of the ACA, accompanied by an increase in the ACA time-averaged velocity, but no change in the ICV time-averaged velocity.