First sign of hydrocephalus in children is:
Post clinoid erosion
Large head
Sutural diastasis
Thinned out vault
In infants the diagnosis of hydrocephalus is confirmed by USG (as the fontanel are open) and in most cases it tells about the level of obstruction & cause (like dandy walker & arachnoid cyst.) Investigation of Choice for Hydrocephalus Infant's older patients low pressure(Hydrocephalus Elderly) Ultrasonography CT / MRI MRI