RESUMO
1. Any present day definition of hydrocephalus is very loose. The authors would rather adopt the concept that hydrocephalus is an abnormal condition characterized by excessive amount of cerebrospinal fluid with or without enlargement of the head2. The most common cause of hydrocephalus is arachnoiditis followed by congenital anomalies. A neoplasm is a rare cause3. The ideal surgical procedure is the placement of a ventriculoatrial shunt, using either Pudenz or Halter valves. Where these valves cannot be availed of the choice is between a conservative waiting with medical support and ventricular tapping from the older surgical shunting procedures, like ventriculo-peritoneal, chroroidoplexectomy, thecal-fimbia, subarachnoid-ureteral, and others. (Summary)