Pre-natal ventriculomegaly and hydrocephalus

Ultrasonic imaging of the human fetal brain has allowed ventriculomegaly an d hydrocephalus to be categorized. In this study 40 fetuses with ventriculo megaly and 21 with an Arnold-Chiari malformation and a myelomeningocele had ventriculomegaly that resolved, stabilised or progressed in utero. Within the progressive group were those with hydrocephalus, hydrocephalus being de fined as expansion of the cerebral ventricular atria together with dispropo rtionate increase in the head circumference. The prognosis for fetuses with resolving and stable ventriculomegaly was good, reflecting the fact that t he ventricular dilatation in these cases was probably caused by delayed par enchymal and cerebrospinal fluid pathway development Whereas the prognosis for progressive ventriculomegaly was generally poor, suggesting that the ca uses were likely to have been chromosomal, genetic, an infective agent or a catastrophic event which had an adverse effect on parenchymal development. The causes of hydrocephalus also adversely affected brain development but additional damage was caused by raised intracranial pressure.