RESUMO
Hypodipsic hypernatremia is characterized by chronic or recurrent episodes of severe hypernatermia associated with dehydration and a lack of thirst. This constellation of deficits suggests that the syndrome is due to hypodipsia of destruction of the hypothalamic osmoreceptors that regulate thirst and ADH secretion. We report a child with abnormalities of the central nervous system who had hypernatremia and a lack of thirst without detectable abnormalities in the osmoregulation of ADH secretion. The patient was a 11 month old female and her chief complaints were poor oral intake and weight gain. There were recurrent hypernatremia with hyperosmosis and normal level of plasma ADH. With intravenous rehydratin, oral intake was improved and plasma sodium level decreased.