Changes in the visual evoked potentials of hydrocephalic children.

The visual evoked potentials (VEPs) of a group of 84 hydrocephalic children, aged between 2 days and 15 years, were studied. The variables analyzed were age, ventriculomegaly, head size, and the presence or absence of a functioning shunt. In infants, an increase in the latency of the primary positive wave (P2) was confirmed, but this was present consistently only when ventriculomegaly was accompanied by increased head size. Improvement in the VEP was slow to follow shunting. No change in the latency of P2 was found during hydrocephalic episodes in older children.