Abnormal regulation of thirst and vasopressin secretion following surgery for craniopharyngioma.
OBJECTIVE
In this study we aimed to establish the frequency of postoperative diabetes insipidus and the incidence and characteristics of abnormalities of thirst in a cohort of patients with craniopharyngioma, in whom neurosurgery had been performed.


METHODS
Diabetes insipidus was determined by either standard criteria for diagnosis in the immediate postoperative period, or by water deprivation test, in all craniopharyngioma and pituitary tumour patients who underwent surgery in Beaumont Hospital between the years 1986 and 1998. Osmoregulated thirst and vasopressin release were studied during a 2-h infusion of hypertonic (5%) saline followed by a 30-min period of free access to water.


METHODS
Data on the incidence of postoperative diabetes insipidus was collected in 26 patients with craniopharyngioma and 154 patients with pituitary adenomata. We recruited 16 healthy control patients, 16 patients with cranial diabetes insipidus following pituitary tumour surgery and 16 patients with cranial diabetes insipidus following craniopharyngioma resection for the hypertonic saline infusion study.


RESULTS
Twenty-five patients out of 26 (96%) patients developed diabetes insipidus after surgery for craniopharyngioma, a much higher incidence than after surgery for suprasellar (26/88, 30%, P < 0.001) or intrasellar pituitary tumours (9/66, 14%, P < 0.001). Hypertonic saline infusion identified abnormal thirst responses in five of the 16 craniopharygioma patients studied; all of the pituitary tumour patients had a normal thirst response. Three of the craniopharyngioma patients had adipsic diabetes insipidus whilst two had polydipsic diabetes insipidus.


CONCLUSIONS
This study demonstrates following surgery for craniopharyngioma there is a high incidence of cranial diabetes insipidus and a significant incidence of abnormal thirst responses to osmotic stimuli.
Academic Department of Endocrinology, Beaumont Hospital, Dublin, Republic of Ireland.
D
D
Smith
F
F
Finucane
J
J
Phillips
P H
PH
Baylis
J
J
Finucane
W
W
Tormey
C J
CJ
Thompson
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D003397:Craniopharyngioma / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D003919:Diabetes Insipidus / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D004326:Drinking; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D009994:Osmolar Concentration; D010911:Pituitary Neoplasms / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D012462:Saline Solution, Hypertonic; D013894:Thirst / Q000502:physiology*; D014667:Vasopressins / Q000097:blood* / Q000378:metabolism
D012462:Saline Solution, Hypertonic; D014667:Vasopressins