Cerebrospinal fluid pressure during post haemorrhagic ventricular dilatation in newborn infants.

Post haemorrhagic ventricular dilatation occurs in a minority of newborn infants, but is associated with a high risk of cerebral palsy and developmental delay. Neither the relation of ventricular size to cerebrospinal fluid (CSF) pressure, nor the effect of CSF removal on prognosis, have been established. Normal CSF pressure measured at subarachnoid cannulation was mean (SD) 2.8 (1.4) mm Hg. Values were significantly higher in post haemorrhagic ventricular dilatation--9.1 (3.7) mm Hg when the ventricles were expanding, and 4.5 (2.4) mm Hg when they were static or contracting. No significant relation between head circumference and CSF pressure was found in this series. Raised CSF pressure is associated with progressive ventricular dilatation, and may contribute to the increased risk of neurological abnormality.