Introduction Endoscopic third ventriculostomy (ETV) is a standard procedure for the treatment of obstructive hydrocephalus in children and adults. Perforation of the third ventricle floor which is part of the hypothalamic-pituitary neuronal network is the key of this surgical procedure. Single patients with endocrine or electrolyte abnormalities after ETV have been reported in children or adults. So far there are no prospective data available about the endocrine effects after ETV.~Materials and methods 40 patients (10 children, 30 adults) with obstructive hydrocephalus and inclusion criteria will undergo ETV in our neurosurgical department. Complete hypothalamic-pituitary hormonal evaluation will be done, in children and adults, before the procedure and at 3 and 12 month after ETV. At 3 month, a brain MRI, with hypothalamic-pituitary specifics sequences, will be performed and compared to the preoperative one. Follow up will be at 3 and 12 month after ETV.~Interventions: ETV is performed under general anesthesia with a rigid endoscope. Perforation is made just behind the clivus, halfway between the infundibulum and the mammillary bodies in the midline using a monopolar electrode, followed by dilatation with an inflated balloon catheter. In our department, this procedure is performed only by 2 senior surgeons.~Number of subjects: 40 patients: 10 children, 30 adults. Statistical analysis: stratified analysis.
Background: Endoscopic third ventriculostomy (ETV) is a standard procedure for the treatment of obstructive hydrocephalus in children and adults. Perforation of the third ventricle floor which is part of the hypothalamic-pituitary neuronal network is the key of this surgical procedure.~Purpose: There are no prospective data available about the endocrine effects after ETV in children and adults. The principal aim of this prospective study is to evaluate the variability of hypothalamic-pituitary hormones and clinical effects in children and adults after ETV in order to plan a multicentric study.