[Diabetes insipidus after endoscopic third ventriculostomy. A case report and review of the literature].

Endoscopic third ventriculostomy has been found to be successful for treating occlusive hydrocephalus. The complication rate ranges from 6 to 12%. Intraoperative bleeding is the most common incident. Endocrinological failures are rare, mainly due to the proximity of the hypothalamic structures. We report the case of a 33-year-old man who was referred in emergency for subacute hydrocephalus related to a tentorium meningioma. The hydrocephalus was treated by endoscopic third ventriculostomy. During the procedure, the floor of the third ventricle was found to be thick but fenestration was performed without incident. After surgery, the clinical signs of hydrocephalus disappeared but diabetes insipidus was diagnosed the same day. There were no other endocrinology disorders. Medical treatment with vasopressin allowed resolution of the diabetes insipidus in fifteen days. Surgical debulking of the meningioma was then achieved via a subtemporal approach. There was no recurrence of the endocrinology disorder. Diabetes insipidus is an unpredictable complication of third ventriculostomy. The mechanism is not well known. It is however a transient disorder that can easily be treated with vasopresin and therefore should not modify the indications of third ventriculostomy, especially in tumor-related hydrocephalus.