Menière's disease in congenital nephrogenic diabetes insipidus: report of two twins.

Two cases, twins, affected by congenital nephrogenic diabetes insipidus (CNDI) with a high daily volume of dilute urine excretion and periods of compensatory high levels of antidiuretic hormone (ADH) simultaneously developed a fluctuating Menière-type hearing loss. It is well known that the kidney and the cochlea are linked by structural and anatomic characteristics, as well as by the physiologic mechanism of electrolytes and fluid regulation. The patients herein described seem to be paradoxical, because they suffered from hydropic hearing loss despite the pathophysiologic mechanism of CNDI and the possible role played by ADH in water regulation in the inner ear. The consequences on Menière's disease of the different therapeutic regimens followed by the two CNDI patients are discussed. To our knowledge these are the first cases of CNDI with Menière's disease described in the literature.