Abnormalities of water metabolism in children and adolescents following craniotomy for a brain tumor.

We conducted a retrospective analysis of the cases of 122 children operated on for various brain tumors, to determine the incidence and natural history of postoperative diabetes insipidus (DI), and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Abnormalities of water homeostasis were observed in 15 patients (12%). DI, with or without SIADH, was observed in 10 patients (8%), while SIADH alone was seen in five (4%). DI was permanent in five subjects (50%), whereas SIADH resolved completely in all affected individuals. Parenteral desmopressin (dDAVP) was an effective mode of therapy in the postoperative period. The effect did not correlate with a dosage strictly based on body weight.