title: Recurrent hypernatremia; a proposed mechanism in a patient with absence of thirst and abnormal excretion of water.
abstract: A 7-year-old girl twice developed severe hypernatremia (serum sodium values up to 194 mEq/l) without obvious cause. The ability of her kidneys to conserve water was normal, and increasing her plasma osmolality stimulated an appropriate ADH response. Unable to excrete a water load, her kidneys continued to conserve water even with a serum sodium concentration of 133 mEq/l. She was never thirsty and did not ingest sufficient fluid by choice. Although there was no demonstrable anatomic lesion, we postulate a localized defect of her thirst center. This may have modified release of ADH and resulted in an inability to dilute the urine by interrupting a pathway that could exist from the thirst center to the supraoptic nuclei. A therapeutic regimen based on these studies has prevented further hypernatremia.
mesh_terms: D002648:Child; D002675:Child, Preschool; D004326:Drinking; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D006955:Hypernatremia / Q000209:etiology* / Q000628:therapy / Q000652:urine; D007263:Infusions, Parenteral; D012008:Recurrence; D012462:Saline Solution, Hypertonic; D013894:Thirst; D014667:Vasopressins / Q000378:metabolism; D014883:Water-Electrolyte Imbalance / Q000209:etiology* / Q000628:therapy / Q000652:urine
chemical_list: D012462:Saline Solution, Hypertonic; D014667:Vasopressins; D005947:Glucose