SUBOCCIPITO-VAULT SKULL DIAMETER: AN EARLY INDICATOR OF VENTRICULAR DILATATION IN PRETERM BABIES

The distance between the inferior surface of the occiput and the superior surface of the vault of the skull was measured weekly during the first nine weeks of life in 56 preterm but appropriately grown babies with birthweights less than 1850g. For seven babies with dilatation of the cerebral ventricles (shown by ultrasonography) the suboccipito-vault height increased above the 97th centile within the first five weeks of life, although over the same period the occipitofrontal head circumference did not exceed the 75th centile. In the only other baby with ventricular dilatation the suboccipito-vault height did not increase while therapy with frequent removal of lumbar cerebrospinal fluid was performed. Suboccipito-vault height is a sensitive early indicator of progressive dilatation of the cerebral ventricles, and may be of value in centres without ultrasound facilities.