Aetiology and treatment response in patients with spontaneous diabetes insipidus.

BACKGROUND: Spontaneous diabetes insipidus (DI) is an uncommon disorder. This study analysed aetiology and response to treatment in patients with spontaneous DI admitted to the endocrinology service of a teaching hospital. METHODS: Twenty patients were seen over a eight year period (1991-1998). The diagnosis of DI was confirmed in each case by the standard water deprivation test. Appropriate diagnostic procedures were carried out to determine aetiology. RESULTS: Sixteen patients had complete DI and four patients had partial DI. Eighteen had central DI and two nephrogenic DI. The etiology in sixteen of the eighteen patients with central DI included: histiocytosis--three, eosinophilic granuloma--two, neurosarcoidosis--three, viper-bite--one, head injury--two, germinoma--one, post RT--one, tuberculous meningitis--one, acute-sphenoid sinusitis--one and hypothalamic tumour--one. Eleven patients (61%) responded to tab. carbamazepine, while nine (45%) required intra-nasal DDAVP. One of the two patients with nephrogenic DI responded to thiazide diuretic. CONCLUSION: We identified the aetiology in 88% of our patients with central DI. Histiocytosis and sarcoidosis accounted for 40%. Most patients (61%) responded to treatment with oral carbamazepine, others required intra-nasal DDAVP.