<prompt> First sign of hydrocephalus in children is :Post clinoid erosionLarge ffieadSutural diastasisThinned out vault  <response>: C i.e. Sutural diastasis In infants, the diagnosis of hydrocephalus is confirmed by USG as the fontanel are openQ and in most cases, it tells about the level of obstruction cause like Dandywalker arachnoid cyst. Also Remember Aqueductal StenosisQ is m.c. of obstructive non-communicating hydrocephalus. Subarachnoid hemorrhageQ which is usually a result of intraventricular hemorrhage in premature infant is m.c. of nonobstructive communicating hydrocephalus. In an infant accelerated rate of enlargement of head is the most prominent sign. Clinical presention is: open anterior fontanelQ, setting sun eye signQ, UMN signs cracked pot macewen signQ on percussion. Skull X Ray shows copper beaten sign, indicative of chronic raised intra cranial pressure ICPQ. In adults, erosion of dorsum sellaeQ occurs earliest in hydrocephalus. 