A 56‐year‐old woman with a history of cerebral aneurysm status post clip placement, seizures, hypertension, diabetes insipidus, obesity, obstructive sleep apnea, and multiple DVTs presented to the ER after being found down in her bathroom by her brother. The patient was unable to relate her medical history or recent events, so history was obtained from her brother and chart review. Chart review revealed multiple prior admissions for both hypernatremia and hyponatremia, as well as “erradic thermoregulatory function.” EMS recorded a temperature of 102 and evidence of urinary incontinence. Physical exam at the time of admission was notable for normal vitals, 4/5 lower‐extremity muscle strength bilaterally, and altered mental status. Laboratory studies were significant for sodium 150, BUN 28, creatinine 1.16, urine osmolality 1029, and urine sodium 120. Imaging ruled out fracture or bleeding as a result of her fall. Epileptiform waves were found on EMG. At this point, the prior diagnosis of DI was questioned because of the high urine osmolality. We decided to proceed with her prior desmopressin dose and D5W with the goal of replacing half her water deficit over 24 hours. Within 24 hours, her serum sodium had dropped further than expected to 138, so both desmopressin and fluids were stopped. The next day, her serum Na had returned to 150. Despite this degree of hypernatremia, the patient denied thirst.
Adipsic central diabetes insipidus (DI) is an unusual disease state caused by damage to the hypothalamus impairing both the thirst osmoreceptors and the vasopressin‐synthesizing neurons, most commonly found following rupture of saccular aneurysms of the anterior communicating artery or surgical excision of craniopharyngioma. Adipsic DI can be challenging to diagnose as patients can present with many possible combinations of serum and urine osmolality, depending on their use of desmopressin (as the DI is typically recognized before the adipsia) or whether a caretaker is encouraging water consumption. Treatment requires establishing the necessary daily volume of water intake and dose of desmopressin to maintain eunatremia. However, these patients have high rehospitalization rates due to their doubly impaired ability to regulate sodium‐water balance.
This case demonstrates the difficulties in both diagnosis and treatment of adipsic DI. Long‐standing adipsia can lead to significant hypernatremia even with the proper use of desmopressin. Treatment requires the help of a diligent caregiver to encourage consumption of approximately 1 L of water daily and to track daily weights, ideally with adjustments in water consumption based on daily weight gain or loss, as well as frequent sodium checks. Even when all these precautions are carried out, patients with adipsic DI have high hospital relapse rates due to hypo‐ and hypernatremia, as well as their many other comorbidities including seizures, DVTs, CAD, OSA, obesity, and autonomic dysfunction.
To cite this abstract:Barbero E, Ramos P. Diabetes Insipidus Without the Thirst. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 326. https://www.shmabstracts.com/abstract/diabetes-insipidus-without-the-thirst/. Accessed December 10, 2018.